Removal of cholesterol by lactobacilli via incorporation and conversion to coprostanol
Removal of cholesterol by lactobacilli via incorporation and conversion to coprostanol
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DOI：
10.3168/jds.2009-2574
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发表时间：
2010-04-01
影响因子：
3.5
通讯作者：
Liong, M. -T.
中科院分区：
文献类型：
--
作者：
Lye, H. -S.;Rusul, G.;Liong, M. -T.
通过测定细胞疏水性，筛选出15株乳酸杆菌和双歧杆菌，根据它们对碳氢化合物的粘附能力。嗜酸乳杆菌ATCC 314，L.嗜酸乳杆菌FTCC 0291、保加利亚乳杆菌FTCC 041.1、L. bulgaricus FTDC 1311和L.干酪素ATCC 393显示出更大的疏水性，因此选择其用于检查胆固醇去除性能。所有选定的菌株显示出细胞脂肪酸组成的变化，特别是总脂肪酸和饱和和不饱和脂肪酸的存在下，胆固醇与那些生长在没有胆固醇。此外，我们发现在含有胆固醇的培养基中生长的细胞比在不含胆固醇的培养基中生长的细胞更能抵抗超声处理和酶裂解。我们通过将荧光探针插入细胞膜进一步评估了掺入胆固醇的位置。在一般情况下，富集的胆固醇被发现在该地区的磷脂尾巴，上层磷脂，和极性头的细胞膜磷脂双层。我们的研究结果还表明，乳酸杆菌能够通过胆固醇转化为粪甾烷醇来降低胆固醇，这得益于菌株产生胆固醇还原酶的能力。我们的研究结果提供了实验证据，以加强假设，益生菌可以通过将胆固醇掺入细胞膜和胆固醇转化为粪甾烷醇来去除胆固醇。所研究的菌株可能是发酵乳制品中潜在的健康辅助培养物，具有可能的体内降胆固醇作用。
Fifteen strains of Lactobacillus and Bifidobacterium were screened based on their ability to adhere to hydrocarbons via the determination of cellular hydrophobicity. Lactobacillus acidophilus ATCC 314, L. acidophilus FTCC 0291, Lactobacillus bulgaricus FTCC 041.1, L. bulgaricus FTDC 1311, and L. casei ATCC 393 showed greater hydrophobicity and, thus, were selected for examination of cholesterol-removal properties. All selected strains showed changes in cellular fatty acid compositions, especially total fatty acids and saturated and unsaturated fatty acids in the presence of cholesterol compared with those grown in the absence of cholesterol. In addition, we found that cells grown in media containing cholesterol were more resistant to sonication and enzymatic lysis compared with those grown without cholesterol. We further evaluated the location of the incorporated cholesterol via the insertion of fluorescence probes into the cellular membrane. In general, enrichment of cholesterol was found in the regions of the phospholipid tails, upper phospholipids, and polar heads of the cellular membrane phospholipid bilayer. Our results also showed that lactobacilli were able to reduce cholesterol via conversion of cholesterol to coprostanol, aided by the ability of strains to produce cholesterol reductase. Our results provided experimental evidence to strengthen the hypothesis that probiotics could remove cholesterol via the incorporation cholesterol into the cellular membrane and conversion of cholesterol to coprostanol. The strains studied may be potential health adjunct cultures in fermented dairy products with possible in vivo hypocholesterolemic effects.